1. Field of the Invention
The invention is directed to a method of adhering a pleated filtration media so that the media has a specified pleat spacing and can be selectively deployed from a folded, stored state and placed in an operational state. The invention is further directed to an article of manufacture being a filtration media stack having adhered pleats at a specific spacing such that the filter media in the stack may be selectively removed from the stack and deployed in as part of a filtration operation.
2. Background of the Invention
Filtration as a field is broadening daily. The need for effective filtration in everything from the air we breathe to the water we drink to the electronics we use daily, all these systems require filtration of a gas or liquid. Dirty filters result in lower flow rates which translate to lower efficiency in air filtration. It is often the case that the used filters require cleaning and/or replacement. A lack of maintenance of such filters means the equipment must run longer to accomplish the intended goals, resulting in increased energy usage. The timing for replacing or renewing these filtration mechanisms is therefore important in both improving efficiency and maintaining operational output in most filtration applications. Longer operational life is an important design parameter.
In addition, another important component in almost all filtration operations is balancing flow through the filter and effective removal of contaminants. To increase surface area while maintaining flow, many filters and filter media have adapted a pleated design to filter the flow. This maximizes the surface area for a given dimension. In providing an effective pleated filter media for a filtration operation, it is often the case that a specific density of pleats or pleat spacing or pleats per inch is desired.
In existing filter designs, for instance in, but certainly not limited to, the Heating, Ventilation and Air Conditioning (HVAC) product space, a filter media is typically laid out and then hot glued to a static frame to fix the spacing. The static media remains adhered in the presence of the inflowing air and filters the particulates. Once the filter becomes sufficiently clogged with contaminants, it is replaced. In other non-limiting HVAC examples, methods exist to adhere media, especially high loft media which does not retain a “memory” to allow for easy pleating, in static application in a manner similar to the non-high loft media. The high loft material uses a wire mesh, plastic lattice or similar structure across the entirety of the material, giving it the ability to be shaped or formed. Similarly in other non-limiting examples, in water filtration for instance, a majority of pool filters have highly compact pleat spacing media for filtering contaminants and often have irregular filter shapes. These are often statically adhered to rubberized frames using non-reactive glues. The static designs are convenient, but the static media his results in shorter operational lifespans.
Examples of such static devices include a number of filters from major manufacturers like 3M, CLARCOR and similar producers. For example, 3M and CLARCOR produce a number of residential and commercial filters with pleated filter media. Such as 3M's FILTRETE or CLARCOR's FRESH AIR SPUPRE AND EXTREME AIR PLUS filters. In most, in these filtration operations these filters are and remain static in nature. Extended lengths of operation for filters, which would reduce maintenance visits and thereby improve efficiency in the deployed filter, can be provided through non-static operation, e.g. movement of the filter media.
There does exist some non-static filters and designs, however these have been extremely limited and typically do not allow for the use of pleated media. Some examples of these types of non-static filters and filter operations include for example U.S. Pat. Nos. 7,186,290, 6,152,998, 6,632,269, 6,491,735, 6,402,822, 6,743,282, 6,632,269, 4,331,576, and U.S. Pat. No. 6,152,998. However, these typically do not utilize a pleated filter media, since movement of the media is difficult to accomplish in a consistent manner. Those that do are larger and more specialized, requiring machinery to complete changes and/or special installations which require additional costs and or maintenance and typically change an entire filter in frame. For instance, in U.S. Pat. No. 7,186,290, a stack of filters is cycled through the device. While potentially convenient, the space taken up by this operation is prohibitive in most instances of filtration processes. A need exists for a more effective system of extending the life of a filter media and using the more efficient pleated filter media.
As noted, most existing filtration applications use a static pleated filter media due to difficulties in handling and moving the media, especially in moving the pleated media and maintaining pleat spacing. When forming a non-static media or when a method of manufacture might benefit from compaction of the pleated filter media, special problems arise in the maintenance of the desired spacing. Additionally, due to the movement of non-static media in a filtration operation it is often also desirable to be able to afford some sealing of the sides of the filtration media to prevent leakage of the flow of gas or liquid being filtered that moves with the media. Further, any solution for securing a specific spacing while providing a means of sealing must also allow for the required selective engagement and movement from a stored to a deployed state in a non-static filtration operation.
To date no such pleated, adhered, spaced filter media is available. As such, a need exists for a method of adhering a pleated filter media to secure a desired spacing, provide sealing, and allow, in the cases of non-static applications, for movement of the media in a non-static filtration operation while providing the aforementioned sealing and spacing.
A further need exists for a device and article of manufacture wherein a length of media is adhered in such a fashion as to provide filtration media in a filtration operation that allows for the filter or filter media stack to secure a desired spacing in the pleated filter media, provide for sealing when the pleated filter media is deployed, and allow, in the cases of non-static applications, for movement of the media in a filtration operation.